MEASURING METHOD OF THE SPECIFIC SURFACE AREA AVAILABLE FOR REACTION OF NOBLE METAL CATALYST IN THE ELECTRODE OF POLYMER ELECTROLYTE MEMBRANE FUEL CELL AND A DESIGNING OF CATALYSTLAYER FOR THE ELECTRODE OF THE SAME FUEL CELL

摘要

A measuring method for determining the specific surface area availablefor reaction of a noble metal catalyst of an electrode for use in a polymerelectrolytemembrane fuel cell. The method includes measuring the total specific surfacearea ofthe noble metal catalyst and the specific surface area of the noble metalcatalyst mixedwith a polymer electrolyte by detecting the adsorption amounts of carbonmonoxideupon exposure to carbon monoxide after reduction in hydrogen, and subtractingthelatter from the former. Also provided is an electrode material for use in apolymerelectrolyte membrane fuel cell having excellent polarization characteristicsbycontrolling the utilization of a noble metal catalyst determined from thetotal specificsurface area and specific surface area available for reaction of the noblemetalcatalyst. The electrode material includes a noble metal catalyst powder and apolymerelectrolyte, wherein the utilization ratio of the noble metal catalyst is atleast 40% ofthe saturation value of the utilization of the noble metal catalyst powder.